Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - Japan to (finally) revise its notoriously lenient JC08 fuel economy ratings test

http://ecomodder.com/forum/attachmen...1&d=1480613282

2016 Prius: is this a 96 mpg US car or a 53 mpg US car?

Depends who you ask!

If you ask the Japanese, it's a 96 mpg car, according to the JC08 test cycle (wiki). But in the States, the Prius (in Eco trim) gets a 53 mpg US EPA combined rating.

Official Japanese fuel economy testing is infamous for producing silly numbers (particularly for hybrids, but also for conventional cars to a lesser extent), and it looks like they're about to do something about it:

Quote:

In a drive to regain public trust, Japan’s JC08 standard for computing fuel economy data will be replaced with the international WLTP mode starting from fiscal 2018 to reflect more real-life driving conditions.

Some credit for this move goes to this year's Mitsubishi JDM fuel economy scandal, where the automaker pumped up tires and generally behaved badly to produce inflated ratings.

But it's interesting that the article also says car owners influenced the move, based on aggregate real world results posted on e-nenpi.com (sort of a Japanese Fuelly) that also fall short of the ratings:

Quote:

In many instances, the gap exceeded 30 percent. For example, high-mileage cars that listed getting nearly 40 kilometers per liter actually averaged less than 30 km per liter, according to Tokyo-based IID Inc., an Internet marketing research firm that includes the site “e nenpi” (good fuel efficiency).
About 650,000 members post their actual fuel consumption numbers to e nenpi.

The new measurement standard will also be adopted in Europe and South Korea.

Full article: New auto fuel-efficiency scores to better show real-life driving?The Asahi Shimbun